1. Field of the Invention
The present invention generally relates to a folding door including a plurality of substantially rigid panels of extruded material with each panel having a female hinge element along one edge thereof and a male hinge element along the other side edge thereof with the hinge elements being continuous throughout the length of the panels and being of unitary construction therewith and more particularly to such a folding door or closure in which a unique locking means is provided to interconnect adjacent panels in a manner to prevent relative longitudinal movement between adjacent panels while permitting relative pivotal movement to enable the panels to fold between extended and collapsed positions.
2. Description of the Prior Art
Folding doors, panels, closures, partitions, or the like, are well known and, in some instances, include hingedly interconnected rigid panels. Prior U.S. Pat. No. 3,486,549, issued Dec. 30, 1969; U.S. Pat. No. 3,516,473, issued June 23, 1970; U.S. Pat. No. 3,670,797, issued June 20, 1972, and U.S. Pat. No. 3,205,935, issued Sept. 14, 1965, are exemplary of prior patents which disclose this type of structure. One of the problems in this type of structure is the hinge connection between adjacent panels. While many hinge connections have been provided between adjacent rigid panels, when extruded panels are used, it is most economical to extrude the male and female hinge elements so that they are formed at the same time as the panel, thus becoming unitary therewith. When the male and female hinge elements are constructed so that interengagement theeof is attained by longitudinal sliding engagement, some arrangement must be provided for preventing relative longitudinal movement after assembly while permitting relative pivotal movement between adjacent panels.